Decorative fountains and water displays which are aesthetically pleasing to the eye are well known, and have been in use since ancient times. The Romans, for example, used public fountains (such as the Trevi Fountain in Rome) as a practical way of reducing incoming water pressure from aqueducts before allowing the water to flow through the urban water distribution system. Aesthetic beauty was produced almost as an afterthought.
In more recent times, fountains have been used solely for their aesthetic beauty. Typical fountains include a pump or other means for delivering water to an elevated position where the force of gravity can act upon the water, causing it to flow back to earth. The path of the water can be free-fall mode, which, in the event of high water pressure, can be very exciting. Alternatively, the flow of water can be very gentle, and a winding path over rocks and through various plants and terrains can be provided, which provides a very soothing, cooling, and natural experience. Some fountains are technologically interesting, providing an apparently seamless film of water flowing down from an elevated source.
Convex surfaces are not typically used in fountains because they provide special problems. Water flowing from the top of a sphere having a smooth surface tends to break into discrete streams and flows down towards the plane (hereinafter referred to as an "equatorial plane") which divides the sphere into an upper hemisphere and a lower hemisphere. When the water flows below the equatorial plane, the film thickness increases as a result of decreasing surface area, allowing the force of gravity to overcome the surface tension, causing the water to shed, or fall off, the surface of the sphere before it reaches the bottom.
Accordingly, the need exists for an aesthetically pleasing fountain incorporating a sphere in which the water appears to flow smoothly across the surface of the sphere from an upper to a lower pole without loss of water shedding from the surface below the equatorial plane as a result of the force of gravity.